It says a lot if you file a trademark application without counsel. And it is in the public record for everyone to see.
Not only will the odds of approval for the application be lower, but if there is ever a dispute involving the brand, others will look at the public records – before sending a letter, or after receiving a letter – and see that the brand owner made a deliberate choice to file on their own.
Because attorney information is in the USPTO’s public records, trademark applicant who file without counsel risk being perceived as not fully invested in protection if someone else is researching their brand – which happens all the time.